Download - Review 3-Phase Ckts
-
Review of 3-Phase AC
Circuits
EE 340
Y. Baghzouz
-
Advantages of 3-Phase
Systems
-
Balanced 3-Phase Systems
-
3-Phase Voltage Source
-
Neutral Wire Sharing
-
Neutral Current
-
Phase and Line Voltages
-
Example of Phase and
Line Voltages
-
Y-Connected Load
-
-Connected Load
-
Power in Balanced 3-Phase Circuits
The real power, reactive power, apparent
power, complex power and power factor are
the same in each phase.
)cos(3)cos(3 IVIVP Lp
)sin(3)sin(3 IVIVQ Lp
Lp VIVS 33
-
Power measurement in 3-phase
4-wire circuit
If the load is balanced,
then P1 = P2 = P3,
hence, PT = 3P1
If the load is
unbalanced, P1P2P3, hence, PT = P1+P2+P3
-
Power measurement in 3-phase
3-wire circuit: the 2-wattmeter method
PT = P1+P2
The load can be Y-
connected, -connected, balanced, or unbalanced.
Any one of the 3 phases
can be used as a
reference.
If the load is balanced,
then P1 = P2, hence, PT =
2P1
-
Measuring active power in a high power circuit
-
Per-Phase Analysis in Balanced
3-Phase Circuits
-
Example of per-phase analysis
Find the complex power supplied by each of the
two sources.
-
Solution
-
Example of 3-phase balanced circuit
-
Problems from Chap 2:
1, 2, 3, 4, 5, 6.